An ultrasonic diagnostic apparatus is known as one of medical image diagnostic apparatuses, and is configured to scan inside of an object's body by using an ultrasonic wave and to image an internal state of the object based on a received signal generated from a reflective wave reflected from the inside of the object's body. An ultrasonic diagnostic apparatus transmits an ultrasonic wave from an ultrasonic probe to the inside of the object's body. Then, the ultrasonic diagnostic apparatus receives a reflected wave generated due to mismatch of acoustic impedance inside the object's body (i.e., difference in acoustic impedance between respective discontinuous planes where the ultrasonic wave is reflected), and generates a received signal based on the reflected wave.
Additionally, an ultrasonic probe is equipped with plural piezoelectric vibrators regularly arrayed in a scanning direction. Each piezoelectric vibrator vibrates based on a transmission signal so as to generate an ultrasonic wave, and generates a received signal by receiving a reflected signal.
Here, an ultrasonic probe in which piezoelectric vibrators are arrayed in both of the first array direction (i.e., the azimuth direction) and the second array direction (i.e., the elevation direction) perpendicular to the first array direction like a matrix has been developed. For instance, a ultrasonic probe equipped with piezoelectric vibrators of 1.5D array type is known. In a scanning operation, an ultrasonic probe of this 1.5D array type can electronically control the piezoelectric vibrators not only in the azimuth direction but also in the elevation direction, and can form a more ideal acoustic field where ultrasonic waves are transmitted and received.
A general ultrasonic probe is configured of, e.g., a piezoelectric body, an electrode layer for applying voltage to the surface of the piezoelectric body, a flexible printed circuit for extracting signals from the electrode layer by wire in an ultrasonic radiation direction of the piezoelectric body, and an acoustic matching layer.
However, in the case of, e.g., an ultrasonic probe equipped with piezoelectric vibrators of 1.5D array type, strength of each piezoelectric vibrator decreases if size of each piezoelectric vibrator becomes fine, and there are concerns of manufacturing failure and decrease in reliability.